Egypt’s presidency declared a three-day mourning period for the attack, as President Abdel-Fattah el-Sissi convened a high-level meeting of security officials. Twitter

At least 200 people have been killed and 125 wounded in a devastating attack on a mosque in northern Egypt.

The BBC reports that on Friday morning, suspected militants targeted worshippers in a synchronised gun and bomb attack on al-Rawdah mosque in Bir al-Abed, west of Arish city in the country's Sinai region.

Local police said men inside four off-road vehicles sprayed bullets at those gathered for Friday prayers at the house of worship, and a bomb was also reportedly detonated near the center of town while the service unfolded, Al Arabiya reported.

"They were shooting at people as they left the mosque," a local resident whose relatives were at the scene told Reuters.

"They were shooting at the ambulances too."

While no group claimed responsibility for the assault, the attack was carried out in a region where Egyptian security forces have battled an Islamic State insurgency that has killed hundreds of police and soldiers over the last three years.

President Abdel Fattah el-Sisi convened an emergency meeting in wake of the deadly attack, and investigative teams, military and police are in the area and "chasing down the perpetrators," a military source told the Guardian.

In addition to killing hundreds of police and soldiers in the region, Islamic extremists have mostly targeted Egypt's security forces and Christian churches. Coptic Christians, who make up just 10% of the country's population of 95 million, have long complained of persecution at the hands of Islamic extremists.

Earlier this year at least 44 people were killed and more than 100 wounded in bomb attacks on two Coptic churches on the Christian festival of Palm Sunday. The group has also indiscriminately targeted Muslims who do not adhere to its extremist ideology.

On Friday, thousands took to Twitter to condemn the attack, many using the hashtag #PrayforEgypt.

Dr. Craig Considine, a Catholic American author and professor, tweeted:

"The attack in Arish (North Sinai), Egypt is a heinous act. If you wanted to illustrate how 'un-Islamic' something is, what better way could you find than the brutal murder of civilians at a mosque during jummah prayer? Reminder: Muslims are most likely to be victims of 'terror.'"

Tweeted the UK's Ambassador to Egypt, John Casson: "I am disgusted by the evil attack that killed & injured so many Egyptians in Sinai today. On behalf of the UK my deep condolences to all involved. These attacks on people praying in mosques & churches only strengthen our determination to stand together, & defeat terrorism & hate."